(a) Field of the Invention
This invention relates to fluid machines which have a rotor or a body with working chambers therein. The body or rotor has a concentric bore, called "rotor hub" and a control body closely fitting therein. The control body has a cylindrical outer face and control parts are provided in the control body and its outer face to control the flow of fluid into and out of the working chambers.
Such machines are, for example, known from my U.S. Pat. Nos. 3,062,151; 3,136,260; 3,223,046; 3,273,342; 3,270,685; 3,277,834; 3,304,883; 3,416,460; 3,747,639; 3,757,648 or 3,468,262 or others.
(b) Description of the Prior Art
It is known from my elder patents, for example, from my U.S. Pat. Nos. 3,062,151; 3,136,260; 3,223,046; 3,273,342; 3,270,685; 3,277,834; 3,304,883; 3,416,460, 3,747,639; 3,757,648 or 3,468,262 or others, to provide a rotor hub in the center of the rotor of a fluid machine which may have either a single or a plurality of working chamber groups in the rotor of the machine.
A control body or pintle is is inserted into the rotor hub and has control ports for the control of flow of fluid into and out of the working chambers of the rotor.
In order to counter balance the fields of pressure which surround the control parts and which include the control ports I have already in my mentioned elder patents provided diameterically located fluid pressure pockets in the control body to build up and maintain therein and therearound counter acting fields of pressure which act in the contrary direction onto the control body and thereby make the control body flat with little or almost no friction in the rotor bore or rotor-hub.
These machines have proven partially to be of high efficiency and greatest reliability and of very little friction at low and medial fluid pressure ranges. They work also satisfactorily temporarily at higher pressures.
However, at the very high pressures in fluid which are presently sometimes desired, a little more friction would be acceptable if the leakage could thereby be reduced.
Recently, a number of patents have been granted to inventors, which have assigned their inventions to the Bosch corporation of Western Germany. Those patents are, for example:
U.S. Pat. Nos. 3,810,418 of Paul Bosch; 3,875,852 of Paul Bosch; 3,866,517 of Ulrich Aldinger, 3,893,376 of Gerhard Nonnenmacher and 3,985,065, also of Gerhard Nonnenmacher.
The latter mentioned patents find equivalent patent application publications (Deutsche Offenlegungsschriften) in Germany. These latter mentioned patents attempt to supply other or better solutions to my first mentioned elder own U.S. patents. However, the latter mentioned patents and applications deal with the same matter as my previously mentioned elder U.S. patents, namely with the centric floating of the control body in the rotor-hub. In all those cases, either the control body floats in the rotor, floats around the control body depending thereon, whether the rotor or the control body is flexibly mounted. At least all these mentioned patents and patent applications claim that the control body would float in a concentrical manner relative to the inner surface of the rotor-hub. As will be shown in the summary of the invention, it is, however, not at all times assured, that the control body always floats concentrically relative to the rotor-hub.
In axial piston pumps or motors it was already customary to press two relative to each other sliding planes or spherical faces together for a good seal. In some of the solutions so applied, it was also already proposed and exercised, to insert thrust bodies into a thrust-chamber. Those solutions are for example shown in U.S. Pat. Nos. 3,800,672 of Walter Kobald; 3,768,377 of William P. Engel, assignor to the Caterpillar Tractor Co., 4,148,249 to Stephan J. Jacobs, wherein a rotor of a radial piston device is axially pressed against a control face and in similar or other patent documents in foreign countries.
It has however never been tried successfully to use thrust bodies of radial direction between a control body and a rotor hub of a radial piston or radical chamber pump or motor.
That is also understandable, because in case of axial thrust arrangements there are plane faces or spherical faces pressed parallel to each other. If now the thrust means of axial piston pumps or motors would be applied to a cylindrical control body in a rotor hub for example of a radial piston machine, the bodies from axial flow devices would not be applicable and in addition the control body would weld on the inner face of the rotor hub, because the faces of the control body and of the rotor-hub would meet in a line, where they would weld.